Home depot, dry lubricant. Spray it on. It reduces surface tension on the dish so snow slides off pretty easy.
Can you be more specific about the product that you have experienced works on dishes ? Brand name ?
I ask because "dry lubricant" seems not to be a generic name for a widely found product ( unlike "white wood glue" or "clear tub & tile silicone caulk" ).
Also, how often do you need to reapply it ? One would think that the snow sliding off cleans the dish of dry lubricant...
Thanks !